A gas turbine engine generally includes a compressor section, a combustion section, and a turbine section. The combustion section typically includes at least one combustor which includes a combustion liner positioned within a combustor casing. The combustion liner may be circumferentially surrounded by a sleeve such as an impingement sleeve and/or a flow sleeve. The sleeve is radially spaced from the combustion liner and a flow or cooling passage is defined therebetween.
In particular configurations, an axially staged fuel injector extends radially through the sleeve and the combustion liner downstream from a fuel nozzle. During operation of the combustor, the liner and the sleeve both expand and contract at different rates as the combustor cycles through various thermal conditions and as such, there is relative motion between these components. In addition, there is relative movement between the combustion liner, the sleeve and the axially staged fuel injector. This relative motion may result in leakage between a high pressure plenum surrounding the sleeve and/or the flow passage and a hot gas path defined within the combustion liner and/or may result in undesirable mechanical stresses between the axially staged fuel injector and at least one of the sleeve and the combustion liner.